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I don't remember, but it seems like we were talking about bonding and grounding csst. I'm trying to remember. I'll call my son-in-law tomorrow to see if he remembers. It may have been a csst booklet I read.

I don't remember, but it seems like we were talking about bonding and grounding csst. I'm trying to remember. I'll call my son-in-law tomorrow to see if he remembers. It may have been a csst booklet I read.

There WAS an issue with CSST and the need for bonding due to a perforation in the steel caused by a lightning strike.

Man... I remember the pre flex days..... I bet people today would just die if they had to run hard pipe off the trunk to the registers in an attic today.

Or a bad crawl space.

Old days? That is what is required again now in all the areas I work in. Insulated hard duct. I had one job where they wanted a second system installed in the attic for a/c only. I figured the hard pipe and insulating it all by hand added probably 20 hours to the job or more plus the material extra cost.

couldn't find the info I was looking for, but did find some material in Tru-flex metal hose corp. installation training guide, that states, and I quote

"Even a nearby lightening strike that does not strike a structure directly can cause metallic systems (such as wiring, piping and ductwork) in the structure to become energized.If those systems are not properly bonded, the difference in potential between the systems may cause the charge to arc from one system to another and cause damage to to csst. End Quote.

Which makes me wonder about the bonding and grounding of the complete system , especially if vibration dampening legs are used on the furnace.Not all furnaces I have seen installed have ground wire.
Also if csst requires # 6 ground, I'm rethinking how a metal duct system should be bonded or grounded, or if it should be.